Percussion drill



Dec. 8, 1931. J. A. PARSONS ET AL PERCUSS ION DRILL Filed Aug. 5, 1929 Patented Dec. 8, 193 1 UNITED. STATES JOHN A. reasons AND Louis 11. ummiestime ess. NEw YoRx rnncossroivhzomL Application filed August 5, 9a1' eaa'm; 383,489.

This invention relates to attachments for rotary drills and has special reference to an.

attachment for rotary drills designed. to convert a rotary drill into a percussion 0r hammer drill. V

One important object of the inventionis to provide an improved device capable of being readily attached to an ordinary rotary electric drill (or, in fact, any type of rotary drill) and which, when so'attached, will enable cement, stone and other like material to be drilled in the same way as though the usual reciprocating drill were employed.

A second important object of the invention is to provide an attachment of this type having the parts compactly arranged and few in number so that it may be used in connection with a rotary drill without adding greatly to the weight or bulk to be handled in the drilling operation.

With the above and other objects in view as will be hereinafter apparent, the inventionconsists in general of certain novel details of construction and combinations of parts hereinafter fully described, illustrated in the accompanying drawings and specifically claimed.

In the accompanying drawings like characters of reference indicate like parts in the several views, and:

Figure 1 is a longitudinal median section through the invention.

Figure 2 is a section, on the line 2-2 of Figure 1.

Figure 3 is a section on the line 33 of Figure 1. V

Figure 4 is a top view of the lower casing closure or head. V

In the embodiment of the invention here shown there is provided a casing having a cylindrical body 10 internally threaded at each end. In the upper or rear end is screwed a closure 11 having a central circular opening 12. wherein fits a journal 13 formed on a driving member having a body'l l fitting in the casing 10 and resting against the inner face of the closure 11. A rib or bottom bearing 13 is formed on the inside of the casing and engages the body or second journal 14 to prevent flotation of the driving member and thusto retain it in proper position-iflthe casing; -'Projecting from the journallis a shanki1'5 shaped'to fit in the tool socket. of thedrill with whichthe attachment is tobe usedi Projecting centrally downward from the'ibfody 14 is-a driving stem 16 polygonal in cross section and fitting in a corresponding opening in a hammer member. This hammer member has a body 17 projecting up from a head18provided, onitslower or forward face with a peripheral series of ratchet teeth the'lower or forward end of the easing 10 is screweda 'head20 provided on its inner trap er facewith a series of ratchet teeth 21fand the head 20 is provided with a socketwherein is slidably fitted the. shank 23 W of aftool24 of any desired-kind. coiled compression spring 25 surrounds the body 17 and bears at one end against the body 14 and at its-otherend againstthe head 18. Proecting-along one side of the casing is a stop 3111126.."

In using the invention the shank 15 is inserted in'th socket of a drill, the stop arm 26 lying alongside the drill to engage oneof its projectingjparts" andthus prevent the attachment from rotating bodily. A suitable tool is now inserted in the tool. socket as shown and the point or edge of the tool placed in position to drill the desired hole. Upon 3 the drill motor being started the driving member will be revolved and will carry with it the upper ratchet member. Since the head 20 is stationary this rotation of the member 18 will cause the ratchet teeth to work over 35 each other, the hammer member alternately rising and falling, the latter being due to the action of the spring. Each time the. hammer member is thrown downwardly or forwardly by the spring the hammer block 22 strikes the g0 end of the tool and thus causes a cutting blow. Obviously, the drill may be turned around during the drilling operation to keep the tool from jamming or wedging.

There has thus been'provided a simple and as efficient device of the kind described and for i v w i the purpose specified. It is obvious that minor changes may be .made in the form and construction of the invention without departing from the mate- 1o.

rial spirit thereof. It is not, therefore, de sired to confine the invention to the exact form herein shown and described, but it is desired to include all such as properly come within the scope claimed.

Having thus described the invention, what is claimed as new, is:

In an attachment for rotary drills, a casing cylinder, a head at the upper end of the cylinder having a bearing opening axially of the cylinder, a driving member in said cylinder having a journal portion fitting in said opening and provided with an outwardly extending shank adapted to fit a drill socket, an annular flange on said member fitting the cylinder and bearing against said head, an annular rib on the inner wall of and extending around said cylinder in engagement with the peripheral portion of said flange, whereby the flange and the head and rib form thrust bearings and the under surface of the central part of the flange is exposed within the rib annulus, a head at the lower end of the casing having a drill shank receiving opening axially ofthe cylinder, a hammer member rotatable and longitudinally slidable in the cylinder and having a boss on its upper end of considerably less diameter than the internal diameter of the rib, a spring surrounding said boss and bearing at one end against the hammer member and seated at its other end against the flange within the rib annulus, cooperating peripheral crown ratchets on the hammer and lower head for raising the hammer against the action of the spring upon rotation of said hammer, and means connecting the driving member and hammer to rotate the latter upon rotation of the former.

In testimony whereof we afiix our signatures.

JOHN A. PARSONS. LOUIS H. HARTMANN. 

